The present invention relates to a method of manufacturing a semiconductor apparatus, a semiconductor production equipment and a cleaning method thereof, more specifically relates to a method of forming a CVD thin film on a surface of a semiconductor substrate, a method of etching a semiconductor substrate, and a method of cleaning a CVD unit and a CVD reactive chamber.
When a thin film is formed by a CVD method on a semiconductor substrate, in a conventional method, a reactive gas (for example, a silane SiH4) as a gas flow 5 for film formation is supplied from outside to an upper portion of a substrate 2 placed on a suscepter 8 provided into a reactive chamber 1 of a CVD unit, shown in FIG. 5.
Gas in supplied via a value 5. A flow rate of the gas is controlled by a mass flow controller 7 so that pressure in the reactive chamber 1 is adjusted to be reduced to about 10 Torr while monitoring a pressure gauge 13. Then, the substrate 2 and the suscepter 8 are heated to 650.degree. C. by an external lamp 3 through a quartz-made wall of the reactive chamber 1, while flowing the gas of 1 slm, so that a polycrystal silicon film is formed.
At this time, a boundary domain, which is called as a remaining region 4 where a gas does not flow, appears on a surface of the substrate 2, and a gas for film formation is supplied from the gas flow 5 outside the remaining region 4. The gas for film formation is diffused in the remaining region 4 and gets to the surface of the substrate. Then, the gas is decomposed so that a polycrystal silicon film is deposited.
A thickness of the remaining region 4 is influenced by the gas flow 5. When the gas flow is not uniform, nonuniformity occurs in thickness of the remaining region 4. As a result, the supply of a gas to the surface of the substrate 2 becomes non-uniform, a depositing speed is varied, and thus the film thickness is varied. Moreover, the supply of the gas from the gas flow 5 is usually determined by pressure division of the gas in the gas flow 5, however under the above condition, only several percentage of the gas in the gas flow 5 is supplied to the remaining region 4, and thus only several percentage of the gas introduced into the reactive chamber 1 is used for the deposition.
Therefore, most of the gas introduced into the reactive chamber 1 is not decomposed, and passes through a main valve 9, a pressure adjusting conductance valve 12 and a pipe arrangement 11 so as to be discharged out of a chamber by a pump 10. As a result, cost of forming a thin film rises.
As mentioned above, in the conventional method of forming a thin film on the semiconductor substrate by deposition, since availability of a reactive gas for film formation introduced into the CVD reactive chamber is low, there arises a problem that cost of forming a thin film rises.